2-Methoxybenzaldehyde and 2,2-dimethoxyethylamine react in benzene to form an aldehyde-amine condensation reaction, which then reacts with ethyl chloroformate and trimethyl phosphite to generate 8-methoxyisoquinolin-4(3H)-one intermediate Chemicalbook. The intermediate is refluxed and dehydrated with titanium tetrachloride in dichloromethane to generate the intermediate 8-methoxyisoquinoline, which is then demethylated with boron tribromide in dichloromethane at low temperature to generate Isoquinolin-8-ol (8-Hydroxyisoquinoline).
